JP7380683B2 - Adhesive set and structure manufacturing method - Google Patents

Description

The present invention relates to an adhesive set and a method for manufacturing a structure.

Steel plates are generally used for interior and exterior parts such as automobile bodies, front doors, rear doors, back doors, front bumpers, rear bumpers, locker moldings, etc., but in order to meet recent demands for improved fuel efficiency, there is a need for lighter weight. It is being For this reason, plastic materials such as polypropylene are increasingly being used as interior and exterior parts of automobiles instead of steel plates. Note that since plastic materials such as polypropylene have lower strength than steel plates, it is common to add talc, glass filler, etc. to improve the strength.

Urethane compositions have been proposed as adhesives between automobile parts made of plastics such as polypropylene. The urethane-based composition is a one-component composition called a moisture-curing type that cures due to moisture in the air, and an adhesive set consisting of a base resin and a hardener. Two-component compositions are known. Among these, from the viewpoint of workability in the adhesion process, it is possible to secure a sufficient pot life (pot life, the time until the paint starts to harden due to chemical reaction, etc. in multi-component paints) and to enable quick curing. There is a tendency to prefer two-part compositions.

In general, polypropylene base materials have low surface polarity and are difficult to adhere to, so in order to facilitate adhesion, a surface treatment is performed to introduce polar groups into the surface of the base material. Examples of the surface treatment include frame treatment. Furthermore, since it is difficult to directly apply a urethane composition to bond surface-treated polypropylene base materials, each polypropylene base material is pretreated with a primer before being applied. It is common to do so. However, in recent years, there has been a demand for improved adhesion without primer treatment (ie, non-primer adhesion) from the viewpoint of simplifying the process and improving the working environment.

For example, Patent Document 1 discloses a two-part curable composition in which a base agent (first liquid) containing an isocyanate compound and a curing agent (second liquid) containing ketimine are mixed during operation. .

Japanese Patent Application Publication No. 2004-131625

By the way, in flame treatment of a base material, the ratio of introduction of polar groups to the surface of the base material (ie, surface tension (wettability)) can be changed depending on the treatment conditions (for example, the number of times). Therefore, the two-component curable composition used has excellent non-primer properties, even on flame-treated substrates under a wide range of processing conditions (i.e., substrates with different surface tensions (wettability)). It is required to have adhesive properties. However, conventional two-component curable compositions do not have sufficient non-primer adhesion to flame-treated substrates under a wide range of processing conditions, and there is still room for further improvement.

Therefore, the main purpose of the present invention is to provide an adhesive set that allows the preparation of an adhesive that has excellent non-primer adhesion even to substrates subjected to frame treatment under a wide range of processing conditions. purpose.

In order to achieve the above object, the inventors of the present invention have conducted intensive studies and found that by using specific components in the curing agent, the adhesive set can be applied to frame-treated base materials under a wide range of processing conditions. The present inventors have discovered that it is possible to prepare an adhesive having excellent non-primer adhesive properties, and have completed the present invention.

One aspect of the present invention is an adhesive set comprising a base resin and a curing agent, wherein the base resin contains a urethane prepolymer having an isocyanate group as a terminal group, and the curing agent contains a polyol containing an acrylic polyol. Provides an adhesive set containing:

In another aspect, the present invention provides a structure by bonding a first base material and a second base material together via a mixture obtained by mixing the base material and the curing agent in the adhesive set described above. Provided is a method for manufacturing a structure, comprising a step of obtaining the structure.

At least one of the first base material and the second base material may be a polypropylene base material.

According to the present invention, an adhesive set is provided that allows the preparation of an adhesive having excellent non-primer adhesion even to base materials subjected to frame treatment under a wide range of processing conditions. Further, according to the present invention, a method for manufacturing a structure using an adhesive set is provided.

Embodiments of the present invention will be described below. However, the present invention is not limited to the following embodiments. Note that in this specification, a numerical range indicated using "~" indicates a range that includes the numerical values written before and after "~" as the minimum value and maximum value, respectively. Furthermore, in the numerical ranges described stepwise in this specification, the upper limit or lower limit of the numerical range of one step may be replaced with the upper limit or lower limit of the numerical range of another step. Further, in the numerical ranges described in this specification, the upper limit or lower limit of the numerical range may be replaced with the value shown in the Examples.

[Adhesive set]
An adhesive set according to one embodiment includes a base agent and a curing agent. In the adhesive set according to the present embodiment, a mixture (two-component curable urethane composition) can be prepared by mixing the base agent and the curing agent. The mixture (two-component curable urethane composition) hardens over time and can act as an adhesive for bonding substrates together.

(A) The main component contains (a) a urethane prepolymer having an isocyanate group as a terminal group. (A) The main ingredient may further contain (b) an interfacial adhesive component. (B) The curing agent contains (c) a polyol including an acrylic polyol. At least one of (A) the main agent and (B) the curing agent may contain any one of (d) a curing catalyst, (e) carbon black, (f) a filler, and (g) a plasticizer. Each component will be explained below.

<(a) Urethane prepolymer>
Component (a) is a reaction product of a compound having two or more active hydrogen groups and a polyisocyanate compound having two or more isocyanate groups. Component (a) can have an isocyanate group as a terminal group by reacting so that the number of isocyanate groups is in excess. Examples of the active hydrogen group include a hydroxy group (OH group), a carboxyl group (COOH group), an amino group (NH ₂ group), and a mercapto group (SH group). The compound having two or more active hydrogen groups may be a polyol, which is a compound having two or more hydroxy groups (OH groups), and may be (a-1) polyether polyol.

Examples of the polyisocyanate compound include aromatic polyisocyanates in which isocyanate groups are bonded to aromatic hydrocarbons, alicyclic polyisocyanates in which isocyanate groups are bonded to alicyclic hydrocarbons, and the like. Among these, the polyisocyanate compound may be (a-2) aromatic polyisocyanate or diphenylmethane diisocyanate. The compound having two or more active hydrogen groups and the polyisocyanate compound having two or more isocyanate groups may each be used singly or in combination of two or more.

((a-1) Polyether polyol)
Component (a-1) is not particularly limited as long as it is a polyether polyol having two or more OH groups. Specific examples include polyethylene glycol (PEG), polypropylene glycol (PPG), ethylene oxide/propylene oxide copolymer, polytetramethylene ether glycol (PTMEG), sorbitol polyol, and the like. Among these, component (a-1) may be polypropylene glycol (PPG). Further, as for the component (a-1), one kind may be used alone, or two or more kinds may be used in combination.

The number average molecular weight of component (a-1) may be 10,000 or less, 9,000 or less, 8,000 or less, 7,000 or less, or 6,000 or less. When the number average molecular weight of component (a-1) is 10,000 or less, the number of crosslinking points increases and mechanical properties during curing tend to improve. The number average molecular weight of component (a-1) is not particularly limited, but may be, for example, 500 or more.

In this specification, the "number average molecular weight" is calculated using gel permeation chromatography (GPC) using a standard polystyrene calibration curve.
The GPC measurement conditions are as follows.
Measuring instrument: ACQUITY UPLC APC system (manufactured by Waters)
Column: APC XT-900, APC XT-200, APC XT-125, APC XT-45 (manufactured by Waters)
Carrier: Tetrahydrofuran (THF)
Detector: Differential refraction Sample: 0.5% by mass THF solution Calibration curve: Polystyrene

((a-2) Aromatic polyisocyanate)
As the component (a-2), for example, 4,4'-diphenylmethane diisocyanate (4,4'-MDI (monomeric MDI)), 2,4'-diphenylmethane diisocyanate) (2,4'-MDI), etc. Can be mentioned.

The content of component (a) may be 20 to 55% by weight, 25 to 50% by weight, or 30 to 45% by weight based on the total amount of the (A) main agent. When the content of component (a) is 20% by mass or more based on the total amount of the (A) main agent, it tends to be possible to prevent a decrease in the adhesive elongation rate during curing, and the content of component (a) When the amount is 55% by mass or less based on the total amount of the (A) main agent, it tends to be possible to prevent deterioration of adhesive properties after curing.

<(b) Interfacial adhesive component>
As the component (b), for example, (b-1) a hexamethylene diisocyanate multimer having unmodified isocyanurate groups (hereinafter sometimes referred to as "unmodified hexamethylene diisocyanate multimer"), (b- 2) A silane coupling agent having a mercapto group or an amino group, (b-3) a polymer of hexamethylene diisocyanate having an isocyanate group modified with component (b-2) and at least two unmodified isocyanate groups ( (Hereinafter, it may be referred to as "modified hexamethylene diisocyanate polymer.").

((b-1) Unmodified hexamethylene diisocyanate polymer)
Component (b-1) is not particularly limited as long as it is a multimer of hexamethylene diisocyanate having an unmodified isocyanate group, and examples thereof include isocyanurate, biuret, and trimethylolpropane (TMP) adducts. It may be a mass. Commercial products of such trimers include, for example, Sumidur N3300 (trade name, manufactured by Sumika Bayer Urethane Co., Ltd.), Duranate 24A-100 (trade name, manufactured by Asahi Kasei Corporation), and Duranate E402-100 (trade name, manufactured by Asahi Kasei Corporation). (manufactured by Asahi Kasei Corporation). Component (b-1) may be used alone or in combination of two or more.

((b-2) Silane coupling agent having a mercapto group or an amino group)
The silane coupling agent having a mercapto group is a silane compound having a mercapto group (SH group), which is an active hydrogen group capable of reacting with an isocyanurate group, and a hydrolyzable group. Examples of the silane coupling agent having a mercapto group include 3-mercaptopropylmethyldimethoxysilane and 3-mercaptopropyltrimethoxysilane. The silane coupling agents having a mercapto group may be used alone or in combination of two or more. Further, it may be used in combination with a silane coupling agent having an amino group, which will be described later.

A silane coupling agent having an amino group is a silane compound having an amino group ( _NH2 group or NHR group (R: hydrocarbon group)), which is an active hydrogen group that can react with an isocyanurate group, and a hydrolyzable group. . Examples of the silane coupling agent having an amino group include N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, and N-2-(aminoethyl)-3-aminopropyltrimethoxysilane. -(aminoethyl)-3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N-(1,3-dimethyl-butylidene)propylamine, Examples include N-phenyl-3-aminopropyltrimethoxysilane and N-(vinylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane. The silane coupling agents having an amino group may be used alone or in combination of two or more. Further, it may be used in combination with the above-mentioned silane coupling agent having a mercapto group.

((b-3) Modified hexamethylene diisocyanate polymer)
Component (b-3) is a reaction product of component (b-1) and component (b-2). When the reaction product is used as component (b), the reaction product contains, in addition to component (b-3), component (b-1), an isocyanate group modified with component (b-2), and one It may contain a polymer of hexamethylene diisocyanate having an unmodified isocyanate group. When using unmodified hexamethylene diisocyanate trimer as component (b-1), component (b-3) contains an isocyanate group modified with component (b-2) and two unmodified isocyanate groups. It may be a trimer of hexamethylene diisocyanate with. The isocyanate groups modified with component (b-2) in component (b-3) contribute to improving the interfacial adhesive strength with the polypropylene base material, and at least two unmodified isocyanate groups are contained in the curing agent. (c) It can contribute to the formation of crosslinks with the polyol (c).

Component (b-3) combines component (b-1) and component (b-2) in an equivalent ratio of NCO groups in component (b-1) to SH groups or NH groups in component (b-2). NCO group/SH group or NH group). For example, when unmodified hexamethylene diisocyanate trimer is used as component (b-1), since it usually has three NCO groups, the ratio (NCO group/SH group or NH group) is 2.5 to 3. By adjusting the range of 5, component (b-3) having an isocyanate group modified with component (b-2) and two unmodified isocyanate groups can be obtained. The reaction between component (b-1) and component (b-2) may be carried out in the presence of a catalyst. The catalyst may be, for example, the same as the curing catalyst (d) described below. The content of the catalyst can be appropriately set depending on the types of components (b-1) and (b-2). The temperature and time for reacting component (b-1) and component (b-2) may be, for example, 35 to 50° C. for 2 to 5 hours.

The content of component (b) may be 2 to 10% by mass, 2 to 7% by mass, or 3 to 6% by mass, based on the total amount of the main agent (A). When the content of the component (b) is 2% by mass or more based on the total amount of the base material (A), the primerless adhesiveness is improved and a decrease in the adhesive durability between the base material surface and the adhesive is prevented. When the content of component (b) is 10% by mass or less based on the total amount of the (A) main agent, it tends to prevent the adhesive properties from deteriorating during curing.

<(c) Polyol>
Component (c) includes (c-1) acrylic polyol. Component (c) may contain a polyol (c-2) component other than the component (c-1).

((c-1) Acrylic polyol)
Component (c-1) is an acrylic polymer of acrylic acid, methacrylic acid, and their esters, and means an acrylic polymer having two or more OH groups (hydroxyl group-containing acrylic polymer). By including component (c-1) in component (c), it is possible to prepare an adhesive that has excellent non-primer adhesion even to substrates that have been flame-treated under a wide range of processing conditions. Become. The reason for this is not necessarily clear, but examples include polyether polyols such as polyethylene glycol (PEG), polypropylene glycol (PPG), ethylene oxide/propylene oxide copolymers, polytetramethylene ether glycol (PTMEG), and sorbitol polyols. , polyester polyols having an ester bond main skeleton obtained by dehydration condensation of a carboxylic acid and a polyhydric alcohol, all have polar bonds in their main chains. On the other hand, acrylic polyols do not have polar bonds in their main chains and are expected to have lower polarity than the above-mentioned polyols. The present inventors believe that the presence of such a low polar acrylic polyol, which has properties different from those of the above-mentioned polyol, in the curing agent (B) improves non-primer adhesion to substrates treated with different processing conditions. There is.

Examples of copolymer components having OH groups constituting the acrylic polymer having two or more OH groups include hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, and 3-acrylate. Examples include chloro-2-hydroxypropyl, 3-chloro-2-hydroxypropyl methacrylate, and allyl alcohol. Examples of copolymerization components other than acrylic acid, methacrylic acid, and their esters include styrene, α-methylstyrene, vinyltoluene, acrylamide, methacrylamide and derivatives thereof, vinyl acetate, maleic anhydride, and the like. Commercially available products of component (c-1) include, for example, UH-2000 (product name, manufactured by Toagosei Co., Ltd.), UT-1001 (product name, manufactured by Soken Chemical Co., Ltd.), and UH-2190 (product name, manufactured by Toagosei Co., Ltd.). Examples include UH-2041 (product name, manufactured by Toagosei Co., Ltd.) and UH-2041 (product name, manufactured by Toagosei Co., Ltd.). Component (c-1) may be used alone or in combination of two or more.

The number average molecular weight of component (c-1) may be 15,000 or less, 13,000 or less, or 12,000 or less, and may be 2,000 or more, 4,000 or more, or 6,000 or more.

The content of component (c-1) may be 30 to 90% by mass, 40 to 80% by mass, or 50 to 80% by mass based on the total amount of component (c). If the content of component (c-1) is 30% by mass or more based on the total amount of component (c), the adaptability to a wide range of flame treatment surfaces will be improved, and interface failure will occur when peeled off. If the content of component (c-1) is 90% by mass or less based on the total amount of component (c), a decrease in adhesive strength during curing can be prevented. tends to be possible.

((c-1) Polyol other than acrylic polyol (c-2))
Component (c-2) is not particularly limited as long as it is a polyol other than component (c-1) and has two or more OH groups, but for example, the polyether exemplified as component (a-1) above Polyols can be used. The number average molecular weight of component (c-2) may be the same as the number average molecular weight of component (a-1).

The content of component (c) may be 35 to 65% by mass, 40 to 60% by mass, or 45 to 55% by mass based on the total amount of curing agent (B). When the content of component (c) is 35% by mass or more based on the total amount of curing agent (B), it tends to be possible to prevent a decrease in flexibility of the adhesive during curing, and component (b) When the content of (B) is 65% by mass or less based on the total amount of the curing agent, a decrease in strength during curing tends to be prevented.

<(d) Curing catalyst>
As component (d), a known catalyst that promotes a urethanization reaction or a urea formation reaction can be used. Component (d) includes, for example, a tin catalyst, an amine catalyst, etc., and can be appropriately selected depending on the desired curing speed. Examples of the tin catalyst include dibutyltin dilaurate, dioctyltin dilaurate, dibutyltin didecanate, dioctyltin didecanate, tin 2-ethylhexanoate, and the like. Examples of the amine catalyst include triethylenediamine, bis(dimethylaminoethyl)ether, and di(N,N-dimethylaminoethyl)amine.

The total content of component (d) is 0.1 to 10.0% by mass, 0.1 to 5.0% by mass, or 0.1 to 5.0% by mass, based on the total amount of (A) main agent and (B) curing agent. It may be 3.0% by mass.

<(e) Carbon black>
Component (e) may have an average particle size (D50: particle size at 50% value of a volume particle size distribution curve) of 20 to 40 nm or 25 to 35 nm. When the average particle diameter of carbon black is within the above range, the viscosity of the adhesive and the dispersibility of carbon black are adjusted to a more appropriate range, and the workability and strength of the adhesive tend to be further improved. Note that the average particle diameter (D50) of carbon black can be measured by a laser diffraction light scattering method using, for example, "Model LS-230" manufactured by Beckman Coulter.

Commercial products of component (e) include, for example, Monarch 460 (manufactured by Cabot Corporation), Asahi Carbon 70 (manufactured by Asahi Carbon Corporation), Seast 3 (manufactured by Tokai Carbon Corporation), Mitsubishi Carbon 32 (manufactured by Mitsubishi Chemical Corporation). ), Niteron 200 (manufactured by Shin Nikka Carbon Co., Ltd.), and the like.

The total content of component (e) may be 5 to 40% by mass based on the total amount of (A) the base agent and (B) the curing agent. When the total content of component (e) is 5% by mass or more based on the total amount of (A) main agent and (B) curing agent, the strength of the adhesive tends to improve, and when it is 40% by mass or less, When present, the strength of the adhesive tends to be maintained because the dispersibility improves. The total content of component (e) may be 10 to 30% by mass since it can further improve the workability and weather resistance of the adhesive.

<(f) Filler>
In addition to the component (e) above, the components (f) include kaolin, talc, silica, titanium oxide, calcium carbonate, bentonite, mica, sericite, glass flakes, glass fiber, graphite, magnesium hydroxide, and hydroxide. Examples include aluminum, antimony trioxide, barium sulfate, zinc borate, alumina, magnesia, wollastonite, xonotrite, whiskers, and the like.

The total content of component (f) may be 5 to 40% by mass or 10 to 30% by mass, based on the total amount of (A) the main agent and (B) the curing agent.

<(g) Plasticizer>
Examples of the component (g) include phthalate ester compounds, alkyl sulfonate ester compounds, and adipic ester compounds. Specific examples of phthalate ester compounds include dioctyl phthalate (DOP), dibutyl phthalate (DBP), diisononyl phthalate (DINP), diisodecyl phthalate (DIDP), butylbenzyl phthalate (BBP), etc. .

The total content of component (g) may be 5 to 40% by mass or 10 to 30% by mass, based on the total amount of (A) main agent and (B) curing agent.

In addition to the above-mentioned components, at least one of (A) the main agent and (B) the curing agent includes an ultraviolet absorber, a dehydrating agent, a pigment, a dye, an anti-aging agent, an antioxidant, an antistatic agent, a flame retardant, and an adhesive. It may further contain a imparting agent, a dispersant, a solvent, etc.

The viscosity of the base agent (A) at 20° C. may be, for example, 500 to 2000 Pa·s, 750 to 1750 Pa·s, or 1000 to 1500 Pa·s. (A) When the viscosity of the base resin at 20° C. is 500 Pa·s or more, the bead shape tends to be easily maintained when the adhesive is applied. (A) When the viscosity of the base resin at 20° C. is 2000 Pa·s or less, there is no need to apply high pressure when discharging the adhesive, and the adhesive tends to be easily discharged. In this specification, the viscosity at 20°C is the viscosity at 20°C measured using a B-type rotational viscometer (product name: VISCOMETER-TV25H, manufactured by Toki Sangyo Co., Ltd., applicable rotor: No. 7). means.

The viscosity of the curing agent (B) at 20° C. may be, for example, 500 to 2000 Pa·s, 750 to 1750 Pa·s, or 1000 to 1500 Pa·s. (B) When the viscosity of the curing agent at 20° C. is 500 Pa·s or more, the bead shape tends to be easily maintained when the adhesive is applied. When the viscosity at 20° C. is 2000 Pa·s or less, there is no need to apply high pressure when discharging the adhesive, and the adhesive tends to be easily discharged.

When mixing the (A) main agent and (B) curing agent, the equivalent ratio of isocyanate groups (NCO) in the (A) main agent to the hydroxyl groups (OH) in the (B) curing agent (NCO group/OH group), for example, , 1.0 to 5.0. If the equivalent ratio (NCO group/OH group) is 1.0 or more, the proportion of unreacted polyol will decrease when the main resin and curing agent are mixed, so sufficient adhesive properties will tend to be obtained. be. When the equivalence ratio (NCO group/OH group) is 5.0 or less, the presence ratio of isocyanate and prepolymer will be in an appropriate range when the base resin and curing agent are mixed, so that they will not interact with moisture in the air. The reaction rate can be suppressed and sufficient curability tends to be obtained. Note that the isocyanate groups in the (A) main agent are mainly derived from the (a) urethane prepolymer, and the hydroxyl groups in the (B) curing agent are mainly derived from the (c) polyol.

In the adhesive set according to the present embodiment, a mixture (two-component curable urethane composition) can be prepared by mixing (A) the main agent and (B) the curing agent. The temperature and time for mixing the (A) base agent and (B) curing agent may be, for example, 10 to 35° C. and 1 to 5 minutes.

The method of mixing (A) the main agent and (B) curing agent is not particularly limited, and for example, it may be a method of mixing by hand painting using a normal caulking gun, and a method of mixing by hand painting using a normal caulking gun may be used. A method of mixing using a mechanical rotary mixer, a static mixer, etc. using a combination of a pump (for example, a gear pump, a plunger pump, etc.) and a throttle valve may also be used.

The prepared mixture (two-component curable urethane composition) can be cured to become an adhesive for bonding substrates together. The conditions for curing the mixture (curing conditions) may be, for example, 10 to 35° C., 30 to 60% RH (relative humidity), and 3 to 7 days.

A method for manufacturing a structure according to an embodiment includes bonding a first base material and a second base material together through a mixture obtained by mixing the base material and the curing agent in the adhesive set described above to form a structure. The method includes a step of obtaining a body. Examples of structures include vehicle back doors, trunk lids, windshields, spoilers, and the like.

At least one of the first base material and the second base material may be a polypropylene base material. Examples of base materials other than the polypropylene base material for the first base material and the second base material include polyvinyl chloride, acrylonitrile/butadiene/styrene copolymer (ABS), polycarbonate (PC), polyamide (PA), poly( Plastic groups such as methyl methacrylate (PMMA), polyester, epoxy resin, polyurethane (PUR), polyoxymethylene (POM), polyethylene (PE), ethylene/propylene copolymer (EPM), ethylene/propylene/diene polymer (EPDM) materials, fiber-reinforced plastic base materials such as carbon fiber reinforced plastic (CFRP) and glass fiber reinforced plastic (GFRP), and resin compound base materials such as sheet molding compound (SMC). In some cases, the first substrate may be an inner panel of polypropylene substrate and the second substrate may be an outer panel.

The equivalent ratio (NCO group/OH group) of the isocyanate group (NCO) in the main agent (A) to the hydroxyl group (OH) in the curing agent (B) may be, for example, 1.0 to 5.0. The temperature and time for mixing the (A) base agent and (B) curing agent in the adhesive set may be, for example, 10 to 35° C. and 1 to 5 minutes. The conditions for curing the mixture may be, for example, 10 to 35° C., 30 to 60% RH (relative humidity), and 3 to 7 days.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the present invention is not limited to these examples.

[Preparation of base agent intermediate product]
In a kneading container equipped with a stirrer, a nitrogen inlet tube, a vacuum pump, and a heating/cooling device, 80.0 g of EXCENOL 837 (polypropylene glycol, manufactured by Asahi Glass Co., Ltd., number average molecular weight: 6000, number of functional groups: 3), EXCENOL 2020 (polypropylene glycol) , manufactured by Asahi Glass Co., Ltd., number average molecular weight: 2000, number of functional groups: 2) 20.0 g, Monarch 460 (carbon black, manufactured by Cabot Corporation) 45.5 g, Iceberg (calcined kaolin, manufactured by Shiraishi Calcium Co., Ltd.) 91. 0g, 49.7g of DINP (diisononyl phthalate), and 0.02g of KOSMOS29 (tin 2-ethylhexanoate, Evonik Japan Co., Ltd.), and stirred at room temperature (25°C) for 30 minutes until there were no lumps of carbon black. did. Next, the kneading container was heated until the temperature of the contents reached 100° C., the pressure inside the kneading container was reduced to 2.7 kPa (20 mmHg) using a vacuum pump, and the contents were stirred for 1 hour. Next, the temperature of the contents was cooled to 70 ° C., and 24.0 g of Millionate MT (4,4'-diphenylmethane diisocyanate, manufactured by Tosoh Corporation, NCO content: 33.6%) was added to the kneading container. After nitrogen introduction, the contents were stirred for 1 hour. The temperature of the contents was cooled to 40° C., and this was used as a base intermediate product.

[Preparation of adhesive set]
<Example 1>
(base agent)
To the above intermediate base agent, 10.2 g of isocyanurate trimer of hexamethylene diisocyanate (product name: Sumidur N3300, manufactured by Sumika Bayer Urethane Co., Ltd.), N-phenyl-3-aminopropyltrimethoxysilane (product name: The main ingredient of Example 1 was obtained by adding 3.5 g of KBM-573 (manufactured by Shin-Etsu Chemical Co., Ltd.) and 6.8 g of DINP (diisononyl phthalate) and stirring for 10 minutes.
(hardening agent)
In a kneading container equipped with a stirrer, nitrogen inlet tube, vacuum pump, and heating/cooling device, 20.0 g of EXCENOL 2020 (polypropylene glycol, manufactured by Asahi Glass Co., Ltd., number average molecular weight: 2000, number of functional groups: 2), UH-2000 (acrylic Polyol (hydroxyl group-containing acrylic polymer), manufactured by Toagosei Co., Ltd., number average molecular weight: 11000, number of functional groups: 2 or more) 80.0 g, EDP-1100 (polypropylene glycol, manufactured by ADEKA Co., Ltd., number average molecular weight: 260, functional Radix: 4) 2.4g, Monarch 460 (carbon black, manufactured by Cabot Corporation) 35.1g, Iceberg (calcined kaolin, manufactured by Shiraishi Calcium Co., Ltd.) 22.6g, DINP (diisononyl phthalate) 29.3g, BHT (Dibutylhydroxytoluene) 0.4g, dehydrating agent Molecular Sieve 4A (dehydrating agent) 1.2g, and KS-1260 (dibutyltin dilaurate, manufactured by Sakai Chemical Industry Co., Ltd.) 1.4g were charged until there were no lumps of carbon black. and stirred at room temperature (25°C) for 30 minutes. Next, the kneading container was heated until the temperature of the contents reached 100° C., the pressure inside the kneading container was reduced to 2.7 kPa (20 mmHg) using a vacuum pump, and the contents were stirred for 1 hour. The temperature of the contents was cooled to 40° C., and this was used as a curing agent.

<Comparative example 1>
(base agent)
The main ingredient of Example 1 was used as the main ingredient of Comparative Example 1 as it was.
(hardening agent)
The curing agent was prepared in the same manner as in Example 1, except that 80.0 g of UH-2000 was changed to 80.0 g of Excenol 837 (polypropylene glycol, manufactured by Asahi Glass Co., Ltd., number average molecular weight: 6000, number of functional groups: 3). Thus, a curing agent of Comparative Example 1 was obtained.

Non-primer adhesion was evaluated by the method shown below using the above-mentioned main agent and curing agent. Note that the mixing mass ratio of the base agent and curing agent was 1:1.

[Non-primer adhesion]
(Preparation of base material)
As base materials, we prepared an olefin thermoplastic elastomer base material (inner base material of the back door) and a long glass fiber reinforced polypropylene base material (outer base material of the back door), and compared only the long glass fiber reinforced polypropylene base material. Performed frame processing. First, as a pretreatment, the surface of the base material was degreased using isopropanol. Next, the surface of the degreased base material was subjected to flame treatment. Flame processing was performed using propane gas using a Bunsen burner (trade name, manufactured by Wazef Corporation) at a processing speed of 80 mm/s. The flame treatment was applied to the base material 1 to 5 times to produce base materials with different surface conditions. The surface tension of the long glass fiber reinforced polypropylene base material was 300 μN/cm (30 dyn/cm) and 350 μN/cm (35 dyn/cm) for untreated, 1st, 2nd, 3rd, 4th, and 5th treatments, respectively. , 420 μN/cm (42 dyn/cm), 540 μN/cm (54 dyn/cm), 650 μN/cm (65 dyn/cm), and 720 μN/cm (72 dyn/cm). The surface tension was measured using Wetting Tension Test Mixture No. manufactured by Wako Pure Chemical Industries, Ltd. 30, No. 35, No. 42, No. 54, No. 65, water (720 μN/cm (72 dyn/cm)) according to JIS K6768:1999.

(knife cut test)
The mixture obtained by mixing the main ingredients and curing agent of Example 1 and Comparative Example 1 above was applied to the prepared base material to a thickness of 5 mm, and the coated base material was heated at 23°C and 50% RH. A test specimen was prepared by curing at (relative humidity) for 72 hours. For each test piece, the cured mixture (adhesive) was cut with a knife, the cut portion was pinched and pulled by hand to peel it off, and the peeling state was observed (manual peeling test using knife cutting). In Table 1, "CF100" indicates that cohesive failure occurred in the entire adhesive surface (100%) of the mixture (adhesive) after curing, and "AF100" indicates that cohesive failure occurred in the mixture (adhesive) after curing. agent) indicates that interfacial failure occurred over the entire area (100%) of the adhesive surface. In Table 1, those in which both "CF" and "AF" are listed indicate that cohesive failure and interfacial failure occurred at the ratio of the numerical values described to the adhesive surface, respectively. In addition, in this test, the larger the ratio of cohesive failure to the adhesive surface, the better the non-primer adhesion.

Table 1 shows the composition of the materials, and Table 2 shows the evaluation results.

As shown in Table 2, the adhesive set of Example 1 using a curing agent containing a polyol containing component (c-1) had a higher performance compared to the adhesive set of Comparative Example 1 that did not use such a curing agent. The adhesive had excellent non-primer adhesion to substrates that had been subjected to different number of frame treatments. These results indicate that the adhesive set of the present invention can be used to prepare an adhesive that has excellent non-primer adhesion even to frame-treated substrates under a wide range of processing conditions. confirmed.

Claims (4)

An adhesive set composed of a main agent and a curing agent , used for bonding a first base material and a second base material ,
The main ingredient contains a urethane prepolymer having an isocyanate group as a terminal group,
The curing agent contains a polyol including an acrylic polyol,
One or both of the first base material and the second base material is a polypropylene base material,
The other one of the first base material and the second base material is a plastic base material, a fiber reinforced plastic base material, or a resin compound base material,
adhesive set. The curing agent further includes a polyether polyol.
The adhesive set according to claim 1. At least one of the base agent and the curing agent contains a curing catalyst, carbon black, a filler, and a plasticizer.
The adhesive set according to claim 1 or 2. A first base material and a second base material are bonded together through a mixture obtained by mixing the base material and the curing agent in the adhesive set according to any one of claims 1 to 3. a step of obtaining a structure by
One or both of the first base material and the second base material is a polypropylene base material,
The other one of the first base material and the second base material is a plastic base material, a fiber reinforced plastic base material, or a resin compound base material,
Method of manufacturing the structure.